Ukraine's new president caught in US political crossfire

Ukraine's incoming president has been caught up in a drama that could influence the course of the US 2020 presidential election, risking tensions with a crucial ally at a time of crisis with Russia.

Volodymyr Zelensky, a political novice, came to power promising to clean up the ex-Soviet country and has yet to be inaugurated.

But already he faces what analysts call a "dangerous trap" set in the US.

US President Donald Trump's personal lawyer Rudy Giuliani was due in Kiev this week to ensure authorities do not abandon legal investigations which he said could be "very, very useful" for his boss.

Ukraine is conducting several probes involving US citizens that could impact on candidates in the next US election.

Giuliani, however, canceled his visit in a sign of tensions between Washington and Kiev.

One of the investigations is aimed at the Ukrainian company Burisma, owned by a pro-Russian oligarch that employed former US vice president Joe Biden's son Hunter for several years.

The probe is potentially compromising at a time when Democrat Biden has launched his candidacy for the presidency.

A second concerns the possible interference of Ukrainians in the 2016 US election for the benefit of Democrat Hillary Clinton, by leaking compromising documents relating to Trump's former campaign director Paul Manafort.

Manafort has been imprisoned for 7.5 years for fraud related to his lobbying activities in Ukraine with the country's former pro-Russian authorities.

The Ukrainian investigation was welcomed by Trump, whose presidency has been haunted by a probe into Russian interference that allegedly helped him win the 2016 vote.

Moscow has denied this but a report by US special counsel Robert Mueller confirmed Russian operatives tried to help Trump defeat his Democrat rival.

However, it did not find Trump's campaign deliberately reached out to collude with the Russians.

Experts say Zelensky, a comedian who won a landslide election victory last month amid frustrations with the political class, has found himself in a legal minefield with the affair.

"Zelensky is in a dangerous trap," said Alyona Getmanchuk, director of the New Europe Analysis Center in Kiev.

"Either he encourages investigations that benefit Trump's presidential campaign, or he loses the support of the White House," she said.

Angering Washington would be risky for newcomer Zelensky who inherits an armed conflict against pro-Russian rebels that has killed nearly 13,000 in five years and caused serious economic difficulties.

While Trump's 2016 triumph raised fears in Kiev of a rapprochement between Washington and Moscow, the US President has so far appeased these concerns.

Trump unexpectedly called Zelensky to congratulate him on his victory.

But Giuliani, explaining the cancellation of his visit, told Fox News he was "convinced" Zelensky is "surrounded by people who are enemies of the (US) president."

He mentioned, in particular, the lawmaker Sergiy Leshchenko, a former investigative journalist who published documents revealing the millions of dollars Manafort was paid before 2014.